This proposal outlines a synthetic plan directed toward the synthesis of carbonolide B, the aglycone of the antibiotic carbomycin B (magnamycin B). Because of the close structural similarities of carbonolide B to the aglycones of the leucomycin and spiramycin antibiotics, this synthetic approach would be applicable to these macronolides as well. This group of 16-membered macrolides have been shown to active against grampositive organisms, and in part, against gram negative organisms and certain Mycoplasma strains. The leucomycins have been used clinically in Japan. A new approach to the formation of macrolide rings is introduced which centers upon the formation of carbon-carbon bonds as opposed to the more traditional carbon-oxygen bond formation. The utilization of naturally occurring chiral substances as convergent synthons is explored. The methodology developed herein would permit the eventual synthesis of analogs with unnatural chirality in certain positions of the macrolides.